Percutaneous procedures often involve accessing vasculature with elongated instruments, e.g., catheters, deployed in an ordered sequence. Common vasculature access points for such procedures include the femoral artery in a patient's groin area and the radial artery in the patient's forearm, each of which provides direct access to the central vasculature system, including the central venous system. Entry into the femoral and radial arteries is often accomplished via the Seldinger technique, which involves using a hollow needle to poke through a patient's skin, subcutaneous tissue and targeted vessel wall, thereby creating a puncture hole through each layer. After the needle poke, a guidewire is inserted through the needle until a distal end of the guidewire passes through the puncture hole and protrudes into the vessel lumen. The needle may then be removed and additional instrumentation inserted at the same access point into the vessel along the track provided by the guidewire.
Depending on the specific procedure being performed and the characteristics of the patient being operated on, procedural instrumentation may be inserted directly over the guidewire in the absence of an introducer assembly (also known as the “bareback method”). More commonly, however, an introducer assembly is first inserted over the guidewire and fed into the vessel. Such an assembly may include an introducer sheath having a hemostasis valve at its proximal end and coupled with a dilator having an integrated proximal hub. Once a distal portion of the introducer sheath is positioned within the vessel, the dilator is removed by disengaging its proximal hub from the sheath's hemostasis valve and pulling on the hub, leaving the sheath and the guidewire in place to feed a guiding catheter into the vessel. The guiding catheter may be configured to channel a procedural device or assembly, such as a transcatheter aortic valve replacement (“TAVR”) assembly, into and through the vessel to a desired treatment site. In such cases, deployment of the aortic valve replacement is followed by removal of the procedural assembly (minus the valve) and the guiding catheter, leaving the introducer sheath and guidewire in place.
Removal of the introducer sheath and guidewire would leave an exposed puncture hole in the vessel wall, causing internal and external bleeding. To avoid or minimize the effects of this result, the puncture hole created through the vessel wall must be sealed. A common method of controlling the puncture hole is to maintain external pressure (e.g., human hand pressure) over the vessel until the puncture seals by natural clot formation processes. This method of puncture closure typically takes between 30 and 90 minutes, can be uncomfortable for the patient, can result in excessive restriction or interruption of blood flow, and can consume costly time and effort on the part of the hospital staff. Another method of controlling the puncture hole is to implant a sealing device or assembly over the puncture. This method can involve exchanging the procedural introducer sheath with a second, different-sized introducer sheath configured specifically for guiding the sealing device or assembly to the vessel.